Primary source documents are the basis of the study of history. They provide essential details about the setting, timing, and causes of past events, from which historians can make connections and draw conclusions. Modern readers should be aware, however, that primary sources are steeped in the ideologies of their time, and thus reflect the prejudices of their authors. Writers' motivations could have been to persuade their audiences to accept a certain religious or political view, and so the information they present as fact should be analyzed in light of their biases. Even if an author intended to simply describe a situation, his cultural background would have influenced his interpretation of the events he witnessed.